Previously, IUI treatment on the NHS was offered if a man had mild fertility problems, a woman had mild endometriosis, or a couple had unexplained infertility.

However, guidelines now state that IUI shouldn't be offered in these circumstances. Instead, you should be advised to keep trying to conceive through regular unprotected sex for a total of two years. After this time has elapsed, you may be offered IVF.

Availability

The availability of artificial insemination on the NHS varies throughout the UK. In some areas, the waiting list for treatment can be very long. The criteria that must be met to be eligible for treatment can also vary.

IUI is also available from some private fertility clinics. Costs vary, but usually range from around £500 to £1,000 for each cycle of treatment.

What happens

Assessment

Before IUI is carried out, a couple’s fertility may need to be assessed to find out why they are having difficulty conceiving and to determine whether artificial insemination is suitable. Read more about diagnosing infertility.

For a woman to have IUI, her fallopian tubes (the tubes connecting the ovaries to the womb) must be open and healthy, because this is where the sperm will fertilise the egg and how the resulting embryo moves down into the womb.

The fallopian tubes can be assessed using one of three methods:

a laparoscopy – where a thin, tubular microscope inserted through a small cut in the tummy is used to look closely at the womb, fallopian tubes and ovaries

hysterosalpingogram– an X-ray of the womb and fallopian tubes taken after a special dye has been injected

hysterosalpingo-contrast sonography (HyCoSy) – which involves carrying out a vaginal ultrasound scan to check the fallopian tubes for blockages

Timing of treatment

To maximise the chances of success, a cycle of IUI should be carried out just after ovulation. It's difficult to predict exactly when this will occur, but in most women it usually happens between 12 and 16 days after they have their period.

You may be given an ovulation prediction kit (OPK) to work out the date of ovulation with greater accuracy. An OPK device can detect hormones released during ovulation in urine or saliva. Alternatively, blood tests may be used to find out when you are about to ovulate.

Occasionally, fertility medication is used to stimulate ovulation. In these cases, vaginal ultrasound scans are used to track the development of your eggs. As soon as an egg is mature, you will be given a hormone injection to stimulate its release.

IUI using a partner’s sperm

If a couple decides to have IUI using their own sperm, the man will be asked to provide a sperm sample at the fertility clinic by masturbating into a specimen cup, usually on the same day that IUI treatment takes place.

The sperm sample will be "washed" and filtered using special equipment to remove any dead sperm and impurities. The faster-moving sperm will be kept and any slow-moving sperm will be removed. This produces a concentrated sample of healthy sperm.

An instrument called a speculum is inserted into the woman's vagina to keep it open. A thin, flexible tube called a catheter is then placed inside the vagina and guided into the womb. This process is mostly painless, although some women experience mild, short-lived cramping. The sperm sample will then be passed through the catheter and into the womb.

The process usually takes no more than 10 minutes, and the couple should be able to go home shortly after the procedure is finished.

IUI using a donor’s sperm

If a male partner cannot produce healthy sperm, or a same-sex couple are having IUI, frozen sperm from a donor is used.

This can be from someone the couple knows, although sperm is usually obtained from a registered or licensed sperm bank.

Choosing to use donated sperm can be a difficult decision, and a couple will often have counselling before a decision is made by the clinic to proceed. Read more about using a sperm donor.

If a couple decides to have IUI using the sperm of a donor, the same procedure is used. However, a sample of frozen sperm from a donor will be thawed out before being "washed" and inserted into the woman's womb.

The sperm bank can provide information about the physical characteristics of available donors, such as their ethnicity, physical build, and hair and eye colour. This will enable a couple to try to match a potential donor’s characteristics with their own.

Chances of success

Figures from the Human Fertilisation and Embryology Authority (HFEA) suggest that each cycle of IUI with donor sperm has a success rate of:

15.8% for women under 35

11.0% for women aged 35-39

4.7% for women aged 40-42

1.2% for women aged 43-44

0% for women over 44

As well as the woman's age, the changes of success can also be affected by the sperm count and sperm quality (using fresh sperm is associated with higher conception rates than frozen and thawed sperm) and technical aspects of IUI, such as working out the time of ovulation correctly.

Overall, more than half of the women who have IUI will become pregnant during the first six treatment cycles.

If IUI fails after several attempts, your doctor may suggest trying another treatment, such as IVF.

Are there any risks?

Risks involved with IUI are minimal, although some women experience mild cramps similar to period pains.

In cases where medication is used to stimulate ovulation, there is a small risk of a reaction to the medication and a chance of an unintended multiple pregnancy (such as twins or triplets).

You’ll be monitored with ultrasound scans to check for a potential multiple pregnancy and the treatment cycle can be abandoned if necessary to avoid this.